User:JessicaHibbert

Contents

Black & Decker Drill Dissection

Figure 1: Black & Decker Drill Before Disassembly

Figure 2: Black & Decker Drill Control Top

Function

The function of the Black & Decker Light Weight Cordless Drill is to drill screws. The advantage of this battery powered tool is to offer more power than manual screw drivers. Furthermore, the toold is hand-held and lightweight for ease in use and storage.

User Requirements

Motors strong enough to create enough torque to drill screw

Small and handheld for ease of use

Efficient battery use so the battery life will be long enough

Ergonomic design for long use

Noise Control

Possible Engineering Specifications

Powered by 6V (4 AA batteries) – long battery life

Maximum Torque for Battery Power, high torque rating

Powerful motor

How the planetary gears are set up as well as the material they are made of

Low Cost maximizes manufacturer profit, use plastic frame and gears, only using metal for parts that needed to be the strongest

Lightweight --- due to utilization of plastic materials

Using lube – minimize noise control

How It Drills

The motor uses the energy from four 1.5V AA batteries to generate power. This power turns the drive shaft of the drill. This drive shaft is then connected to two planetary gear systems. The second of these gear systems powers and turns the end drill bit shaft. The drill bit shaft is what rotates the inserted drill bit and consequently the screw.

1) The motor is powered by four 1.5V AA batteries.

Figure 3: AA Alkaline Battery

Figure 4: Four AA Alkaline Batteries in Casing

2) The motor then turns the drive shaft of the drill.

Figure 5: Motor of the Black & Decker Drill

Figure 6: Drive Shaft of the Motor

3) The drive shaft is connected to the first of two planetary gear sets. These planetary gears are used to decrease the angular velocity created by the rotating motor shaft. This therefore increases the amount of torque that will be exerted by the drill bit.

Figure 7: One of Two Planetary Gear Systems Connected to Arm

Figure 8: Planetary Gears Outside of Shaft and Arm Connection

4) Finally, the torque created by the rotating drill shaft is transferred to screw through the rotating drill shaft and bit.

Figure 9: Casing of Drill Shaft

Figure 10: Drillbit Rotated by Drill Shaft

Parts

The table belows lists the components for the Black & Decker Drill:

Table 1: Black & Decker Drill Component List

Part #

Part Name

Category

Function

Material

Picture

1

Batteries

Power

Supply Power

4 AA Batteries in Battery Carried - Alkaline Batteries

2

Motor

Power

Converts energy necessary to rotate shaft

Low grade steel and plastic

3

Exterior Casing

Frame

Ergonomic design to protect interior components and to conform to users hand; controls readily available for pinky and thumb use

Plastic with rubber grips

4

Motor Shaft

Power

Turns planetary gears as well as acts as teh conversion between the motor power and the torque created by the shaft

Hardened steel

5

Planetary gear system (double)

Torque

First set of three is powered by the motor shaft - this set is then connected to a second set of three gears that power the actual drill shaft

Both sets of gears are made of plastic - gears closed to drill bit are made of a higher strength plastic - gears further from drill bit are made of lesser quality plastic

6

Arm

Torque

Convert torque created by the first set of planetary gears to the shaft that goes through the second set of planetary gears